PROBLEM TO BE SOLVED: To solve such a problem that when the time required for mode transition processing on the generator side varies due to impact of the preceding and following imaging modes, in an imaging system, the mode transition time may be prolonged depending on the timing, if the repeat cycle of read and standby in the initialization driving of the sensor is long.SOLUTION: An imaging device has an X-ray detector where a plurality of pixels are arranged in matrix, control means for controlling the reading of electric signals from the plurality of pixels to be selected and executed in units of row, detection means for detecting instruction of start of imaging mode, and acquisition means for acquiring an imaging mode related to instruction. In the reading of electric signals during mode transition period, where transition is made from a first imaging mode to a second imaging mode different therefrom, the control means controls to select a plurality of rows simultaneously.SELECTED DRAWING: Figure 1
